Research has shown that in addition to the classical visual cortical pathway, there is an "ancient", rapid subcortical pathway responsible for the rapid processing of emotion-related information both consciously and unconsciously. This pathway consists of the superior colliculus, pulvinar, and amygdala and bypasses the primary visual cortex. Our study shows that this pathway is also responsible for processing visual topological information, and that the visual cortex is not related to topological information processing. Based on these findings, we believe that in early stage of vision, the brain detects signals involving life or safety, putting the brain into an alert state, which is essential for the survival of the species. Therefore, in the early stage of vision, the objects to be detected are only "appearing" and "disappearing", not "texture", "shape", etc. Both "appearance" and "disappearance" are changes in topological features. The presence of topological perception and subcortical pathways may be the neural basis for early warning. In primates, the peripheral area of retina is distributed mainly with rod cells, the visual information processing in this area is mainly processed by subcortical visual pathway, this type of retinal structure appeared in more than one hundred million years ago. The area close to the center of the retina is the fovea, the visual information processing in this area is mainly processed by visual cortex, cone cell density increased greatly, the visual spatial resolution becomes very high. This structure emerged only 50 million years ago, so our eyes span at least 50 million years from the peripheral region to the central region. It is a Mosaic of an older structure and a younger one, and their coexistence gives us perfect vision. When we consider the significance of the existence of subcortical visual pathway, we should also consider the function of cortical pathways.